1. Field of the Invention
The present invention pertains to minimally invasive surgical procedures and, more particularly, to minimally invasive procedures for collecting tissue at obstructed anatomical sites.
2. Discussion of the Related Art
Endoscopic or minimally invasive surgical procedures have become well accepted due to the reduced trauma and recovery time for the patient as well as the associated decrease in hospitalization time and cost. It is desirable to expand the types of procedures that can be performed using minimally invasive techniques; however, for such procedures to be universally accepted, the procedures must be capable of being performed in, at most, the same time required for the same procedure performed by open surgery and must be capable of being performed by surgeons of varying degrees of skill.
There are many areas of surgery to which it would be desirable to extend minimally invasive techniques, and one such area is the treatment of tissue disposed at portions of the anatomy other than portions, such as anatomical cavities, providing sufficient space to perform procedures. The terms "tissue" and "organ structure" are used herein synonymously and include portions or the entireties of all anatomical parts including malignant and benign growths and tumors. Examples of such areas of treatment include, for example, preperitoneal hernia repair, bladder neck suspension, separation or dissection of connected or adhering tissue and excision or biopsy of masses or tumors within anatomical parts such as the breast or the brain, and the like. When procedures are performed in cavities such as the abdomen and thorax, conventional retractors or other tissue manipulators can normally be used for exposure of tissue to be treated; however, where the tissue to be treated is located in obstructed anatomical sites such as in very small cavities, in potential cavities such as between layers of anatomical walls, in non-layered or homogeneous tissue or in a single layer of tissue, visualization of the operative site is obstructed as well as is space for maneuvering instruments making minimally invasive surgery extremely difficult to perform in an acceptable manner. As used herein, the term "obstructed site" refers to anatomical spaces or cavities of such a small size that procedures cannot be visualized and/or performed as well as anatomical locations where no space or cavity exists. In the latter case, the obstructed site includes "potential spaces or cavities", such as between layers of anatomical wall that can be separated or spaced such as the peritoneum, fascia and muscles of the abdominal wall and the epidural spaces between the dura matter and the brain and spinal cord, between tissue structure that is normally connected, adhering, closed or collapsed and locations within homogenous tissue that is not separable on a layer-by-layer or constituent basis such as the breast, the brain and the lung.
Tumors or other abnormal, atypical or suspicious growths or changes in anatomical tissue generally must be biopsied to determine whether the growths or changes are benign or malignant. Where a growth is malignant, it is desirable to remove the growth to prevent malignant or cancerous cells from metastasizing or spreading to other portions of the patient's body. However, certain benign growths need not be removed and can merely be monitored. Accordingly, it is common to collect or obtain a tissue specimen of an abnormal or atypical growth or changed area to determine the characteristics of the growth or changed area and the optimum protocol for dealing with the growth or changed area. The procedure of collecting and analyzing a tissue specimen is known as "biopsy".
In the area of breast biopsy, traditional biopsy methods involve making an incision in the breast tissue to collect a tissue specimen in an open surgical procedure. However, this often requires general anesthesia and leaves a significant scar. Endoscopic or minimally invasive surgical procedures are preferred for obtaining specimens of growths due to the reduced trauma and recovery time for the patient as well as the decreased hospitalization time and costs associated with such procedures. One minimally invasive procedure, known as "needle biopsy", uses a needle inserted through soft tissue and into a tumor or the like to remove a specimen of the tumor. However, a specimen obtained through conventional needle biopsy procedures is ordinarily small. Also, without a reliable device to dissect or cut the specimen, other than the needle itself, the needle often has to be inserted into the anatomical tissue several times before an adequate specimen is collected. Further, due to the small size of needle biopsy specimens, the nature of the abnormality is often misdiagnosed, resulting in unnecessary surgery to remove the abnormality or the failure to remove a dangerous, malignant abnormality.
When a growth is diagnosed as being malignant or otherwise dangerous, the growth is often removed surgically. Conventionally, this is accomplished by open surgical techniques in which the tumor and surrounding tissue are dissected and removed through a relatively large incision. The amount of surrounding tissue removed depends on the characteristics and size of the growth. In the case of breast cancer, the entire breast is often removed, resulting in disfigurement of the patient and the need for reconstructive surgery. More recently, it has become acceptable to remove only the growth and a relatively small portion of surrounding tissue in a "lumpectomy" procedure to reduce trauma and the need for reconstructive surgery. However, even lumpectomies are accomplished through an open incision. Also, tissue covering the growth is dissected in order to access the growth with conventional surgical implements. Accordingly, disfigurement and the need for reconstructive surgery are not eliminated.